Engine blower control



Felv 23,1943- D. B. ELFEs ETAL 2,311,936

ENGINE BLOWER CONTROL Filed April 1, 1941 7 1| 'q "gbl 27 29 l2 Il e. ,25 O I.

,Ill l i Snbentor Patented Feb. 3,

UITED STAT ENGNE BLOWER CQNTRL Application April 1, 194i, Serial No. 386,360

(Cl. 12S-119) 8 Claims.

This invention relates to internal combustion engines provided with a blower for supplying air or combustible mixture thereto, at superatmospheric pressure.

The invention is particularly applicable to two stroke cycle engines working under a wide range of speed and load conditions.

it relates particularly to an internal combustion engine with a positive displacement type of blower driven by the engine at a iixed speed ratio. The actual charge requirements oi the engine depend on the load on the engine, so that if the capacity of such a blower is such as to provide suiiicient charge for maximum engine torque at any speed, some means ci reducing .the capacity of the blower ior less than maximum engine torque is required.

'Ihe object of the invention is an engine and blower combination having a regulatable throttle valve in the inlet to the blower, with means for controlling the depression between the throttle valve and the blower inlet, independently of the degree of throttle opening and the blower speed.

A more speciilc object of the invention is an internal combustion engine with a blower having a regulatable throttle valve in the blower inlet, with means for bypassing excess charge from the outlet to the inlet side of the blower, to an extent increasing with the speed of the engine, in any position oi' the throttle valve less than fully open.

.a further object of the invention is an engine blower control in which the bypass valve is opened proportionately to the degree of depression existing between the throttle valve and the blower inlet.

The above and other objects of the invention will be apparent as the description proceeds.

According 'to the invention, the throttle and bypass valves which are balanced buttery Valves, are connected by an interlinkage such that the bypass valve is held closed whenever the throttle valve is fully open. In all other positions of the throttle valve, the bypass valve is moved independently of the throttle valve, in response to changes in the depression on the inlet side ci' the blower, there being lost motion in the interlinkage to permit of this.

The drawing shows the application of the invention to a four-cylinder radial, U-type, twocycle engine.

in the drawing:

Figure 1 is an elevation, partly in section, or a construction according to the invention.

if lr a 2 is a part sectional view on line 2-2 of Figure 1.

The blower i has its inlet side connected to a carburetor i by a pipe 3, and its outlet side connected to the intake ports of an engine 4 by a .pipe 5.

There is a bypass passage 6 around the blower from the outlet to the inlet side thereof.

In. the inlet pipe 3, between the Vcarburetor 2 and the bypass passage 5, there is a balanced butteriiy throttle valve 1 with an operating arm 9, and in the bypass passage there is a balanced butterfly bypass Valve 8, with an operating arm I0.

The throttle valve 1 is moved, manually or otherwise, by a rod il. The bypass valve 8 is moved by a rod i2 which is connected to a diaphragm i@ which constitutes a closure for a chamber i5 which is connected by a pipe I6 to the inlet side of the blower, between the throttle valve 1 and the blower. The diaphragm i4 is subjected to the depression on the inlet side of the blower through the pipe i6.

Movement of the diaphragm i4 upon an increase in the depression in the inlet pipe 3, opens the bypass valve 8 against the pressure of spring means i8 tending to keep the valve 8 closed. The spring means i8 is conveniently disposed in the chamber i5 between the diaphragm I4 and a seating 2d. The seating 2li is mounted on a screw 2i threaded in the wall of the chamber l5 and locked by a nut 22, so that the spring loading may be varied by a turning adjustment of the screw 2i.

Pivotally connected to an arm 2d of the .bypass valve 8 is a rod 25 which slides in a. block 21 pivoted on a lever arm 29 of the throttle valve 1. Between the block 21 and a collar 30 on the rod is a spring 5i. The arrangement is such that the throttle valve 1 and the bypass valve 8 may be moved independently of each other, with relative lost motion between the rod 26 and the block 21, except when the throttle valve 1 is fully open, and the spring 3i is loaded between the block 21 and the collar` 33,130 a suiilcient extent to hold the bypass valve d closed.

The operation of the arrangement is as follows:

In starting, with the engine turning at cranking speed, and with theengine throttle valve either partially or completely closed, the speed is so low that the depression created is insuilicient to lift the diaphragm against the spring pressure thereon, and the bypass valve remains closed, giving full blower output.

In the idling position of the throttle valve, the depression is normally suiicient to open the by- .pass valve to some extent, so that small increases d een ine compensated .ne sexing, only desired lood, over the speed o'otexlned.

,y :end en outlet for s. throttle "telve .rss nesso-ge from le blowen et e nl the liloezearn ne .l ioossege; seid '-ffe to ellen A'es in tine ne blowellettffeen Vtine lnowel'.

t. .ny :tn ,snel eonlbustlon en ltll en inlety end en outlet .for ne throttle Valve in bypass passege from 'le l e the blower, et e fe throttle 'solve ond the blower, s telve ln bypass passage: and, serl n ess velve es the cle selon et the, inlet side of the blower between i tln'ottle 'ifelse end the 'Mower lncreeses, enel moe vente.

3. The lotion oncoming to claim 2, in elllen the snee-ns fior opening end closing the bys eelve, includes s. eloplneem having one side snnjeoteol to ssll'l oensesslon end the other side blower El thro o l we l ttle eine e blowel suoplgfine en sulsjeeteel to stnlospoelo pressure-#the bypass omnes@ the nel" of the oleloesst bypass "valve includes o cllepmeem n me side subjected to seid depression and the other side subjected to atmospheric pressure, tine logo' pese valve being operetively connected .plnegm there beine.: spring means lteen the bypass Valve closed ln onnosltion to e'eet oi the depression on the oleplnem, senno. means being adjustable ond .t tlne seqnlslte spring rate to mointein the densesslon et the inlet side of the blower et tnevelue over the speed ronge of the engine.

6. ln e. two-oycle engine with e eerbtuetor blower between the oerlauretor' nml the engine, e, thottle valve between the eerlauretos enel the blower, means to operate the throttle volvo, e nypess passage between the outlet enti the inlet side of the blower, e byness volvo in the lioness passage, said bypass valve being operated oy the depession et the inlet side of tne blowen between the throttle valve and the lslowei, enel lost motion connecting ineens between the throttle volte enel the bypass valve whereby the nypslss "hielt/e held closed "when the thlottle velwe le tulle' o but movement of the bypass telve lnolo nalen of the throttle valve ls otherwise 7. The combination according to eleinl f5 ln which the bypass volte le eonneetefl to elle phregm which is delected by the depression in opposition. to the pressure of edlusteole seslllent means tending to keep'the hlfgoess solve elosetl.

8. 1in e two-cycle engine o eerlnnetoe, blower net-Ween the oorburotol: enel the engine, throttle Valve between the oen'lometos snol blower, e bypass posseggo l L n. the outlet the inlet side of the ,blower :between the tnlottle valve end the blower, o, bypass "telve in passage controlled by a diaphragm sunjeoteel to the depression between the throttlevelve enel tine blower ond tending to open the bypess voll/e the depression increeses to melntein the leeres sion constant, adjustable spring means opposing' opening movement of the bypsss Valve von lelole to maintain the depression et e, desired velue over the speed ronge of the engine, end e lost motion interllnkege between. the throttle telve end the bypass valve permitting indepenelent movement thereof except in the fully open positl tion o the throttle valve when the loyoess velve' is held closed thereby.

CLARENCE el. 

